Chapter 43 / Motivation, Reward, and Addictive States 1073
Figure 43–4 Positron emission tomography (PET) imaging
reveals neural correlates of cue-induced cocaine craving.
(Adapted, with permission, from Grant et al. 1996.)
A.Subjects were shown neutral or cocaine-related cues and
asked, “How do you rate your craving or urge for cocaine on a
scale of 1–10?” The mean craving score (horizontal bar) is sig-
nificantly higher for exposure to cocaine-related cues than for
exposure to neutral stimuli, even though the magnitude of the
response across individuals varies considerably. Two subjects,
identified by red and blue dots, represent high-level and low-
level craving, respectively.
B.Changes in self-reported craving are correlated with changes
in metabolic rate in the dorsolateral prefrontal cortex and
medial temporal lobe during exposure to cocaine-related cues.
The abscissa plots the difference in metabolic rate between
the two sessions (activity with cocaine cues minus activity
with neutral cues). Metabolic rate is measured as the regional
cerebral metabolic rate for glucose (rCMRglc). The ordinate
plots the difference between the average of the responses to
the question, “Do you have a craving or urge for cocaine?” in
separate sessions with neutral and cocaine-related cues. (Each
session lasted 30 minutes, and in each session, the question
was asked three times.)
C.When subjects report a craving for cocaine, metabolic activ-
ity increases in the dorsolateral prefrontal cortex (DLPFC) and
in two medial temporal lobe structures, the amygdala (Am)
and parahippocampal gyrus (Ph). Pseudocolored PET images
of metabolic activity are spatially aligned with high-resolution
structural magnetic resonance images. Metabolic rate markedly
increased in the amygdala and parahippocampal gyrus in one
subject who reported a large increase in craving during presen-
tation of cocaine-related cues (red dots in parts A and B). This
effect is not evident in a subject who reported no increase in
craving while exposed to the cocaine-related cues (blue dots in
parts A and B). Metabolic activity outside the dorsolateral pre-
frontal cortex and medial temporal lobe is not shown.
B 代谢率的变化
1 背外侧前额叶皮层
6
∆ 渴望
21.5
r = 0.66
p < 0.02
5
4
3
2
1
0
A
自我报告的渴望